Photochemical process for decontaminating gaseous or vaporous streams

Abstract

A process for photochemically treating hydrocarbons and halogenated or partially oxidized hydrocarbons in a gaseous or vaporous mixture, by exposing the mixture to ultraviolet light, preferably of relatively short wavelength in the presence of oxygen or its allotropes, in order to oxidize the hydrocarbons to very simple compounds.

I claim: 
     
       1. A process for photochemically treating a gaseous or vaporous stream containing an oxidizable contaminant, said process comprising exposing said contaminant to ultraviolet radiation from a source of radiation emitting ultraviolet wavelengths shorter than 2100 A in the presence of ozone thereby oxidizing said contaminant to form simple, gaseous products, said ozone being in addition to any ozone formed by said source of ultraviolet radiation. 
     
     
       2. The process of claim 1 wherein said ultraviolet radiation includes components having a wavelength of about 1849 A. 
     
     
       3. The process of claim 2 wherein said contaminant comprises vinyl chloride. 
     
     
       4. The process of claim 1 wherein ozone is present in an amount at least equal to the weight of said contaminant. 
     
     
       5. The process of claim 4 wherein said contaminant comprises vinyl chloride. 
     
     
       6. The process of claim 1 wherein said ultraviolet radiation comprises wavelengths of about 1849 A and said oxidation takes place in the presence of atmospheric oxygen. 
     
     
       7. The process of claim 6 wherein said contaminant comprises vinyl chloride and ozone is present in an amount at least equal to the weight of said vinyl chloride. 
     
     
       8. the process of claim 1 wherein said oxidation takes place in the presence of oxygen. 
     
     
       9. The process of claim 1 wherein said contaminant is present in said stream in an amount of from 10 ppm by volume to 80 percent by volume of said stream. 
     
     
       10. The process of claim 1 wherein said contaminant is irradiated under ambient conditions of temperature and pressure. 
     
     
       11. The process of claim 1 wherein said contaminant comprises vinyl chloride. 
     
     
       12. The process of claim 1 wherein said contaminant is a member selected from the group consisting of a. saturated and unsaturated hydrocarbons containing 2-8 carbon atoms,   b. halogen-substituted saturated and unsaturated hydrocarbons containing 2-8 carbon atoms, and   c. partially oxidized variants of said hydrocarbons and said halogen-substituted hydrocarbons.   
     
     
       13. The process of claim 1 wherein said ultraviolet radiation is provided with energy densities of from 10 watts to 2000 watts per cubic foot.